Environmental Controls on the Growth and Productivity of Diospyros melanoxylon Roxb.: A Critical Narrative Review

Abstract

Diospyros melanoxylon Roxb. is a seasonally deciduous tree of South Asian dry forests whose leaves support a large non-timber forest-product economy. Yet the environmental basis of its growth and productivity remains poorly resolved because commercial leaf output, whole-tree growth, regeneration and reproductive performance are often treated as interchangeable outcomes. This critical narrative review synthesises evidence on climatic, edaphic, topographic, light, disturbance and biotic controls, while distinguishing direct species-level findings from inference based on seasonally dry tropical forest ecology. Live searches of accessible scholarly indexes, repositories, DOI records and institutional databases covered literature published from 1 January 1960 to 24 May 2026, with earlier foundational evidence considered where necessary. The strongest direct evidence identifies plant-available water as a primary regulator of seedling physiology and relative growth, acting through stomatal conductance, photosynthesis and seasonal phenology. Rainfall totals alone are inadequate predictors because soil depth, texture, drainage, rooting access, atmospheric demand and monsoon timing mediate realised water availability. Temperature appears to influence productivity mainly through evaporative demand, phenological timing and interactions with moisture, although controlled species-specific experiments remain scarce. Recurrent fire, grazing, cutting and leaf harvest can preserve a resprouting shrub-like state while simultaneously constraining transition to mature trees and sexual regeneration. Pruning can increase harvestable young-leaf production by stimulating root sprouts, but evidence does not establish that repeated intensive pruning maximises long-term stand productivity or ecological resilience. Climatic niche models indicate broad environmental tolerance, yet they predict habitat suitability rather than leaf yield or demographic persistence. The review concludes that D. melanoxylon productivity is an emergent property of seasonal water balance, site quality, stand structure, disturbance history, genotype and management. Reliable recommendations therefore require multi-site, long-term experiments that measure leaf quantity and quality alongside tree growth, root reserves, recruitment, fruiting, soil condition and associated biodiversity.